package 集合.map;

import java.util.HashMap;
import java.util.Map;

public class Test {
    public static void main(String[] args) {
        Map<String, String> maps = new HashMap<>();
        maps.put("1", "1");
        maps.put("1", "2");

        for (String key : maps.keySet()) {
            System.out.println(maps.get(key));
        }

        Map<Student, String> map = new HashMap<>();
        map.put(new Student(), "1");
        map.put(new Student(), "2");
        System.out.println(map.size());
        for (Student student : map.keySet()) {
            System.out.println();
        }
    }
}
